NetBSD/sys/dev/spi/tmp121.c

144 lines
4.4 KiB
C

/* $NetBSD: tmp121.c,v 1.4 2008/04/04 10:13:59 xtraeme Exp $ */
/*-
* Copyright (c) 2006 Urbana-Champaign Independent Media Center.
* Copyright (c) 2006 Garrett D'Amore.
* All rights reserved.
*
* Portions of this code were written by Garrett D'Amore for the
* Champaign-Urbana Community Wireless Network Project.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgements:
* This product includes software developed by the Urbana-Champaign
* Independent Media Center.
* This product includes software developed by Garrett D'Amore.
* 4. Urbana-Champaign Independent Media Center's name and Garrett
* D'Amore's name may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE URBANA-CHAMPAIGN INDEPENDENT
* MEDIA CENTER AND GARRETT D'AMORE ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE URBANA-CHAMPAIGN INDEPENDENT
* MEDIA CENTER OR GARRETT D'AMORE BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: tmp121.c,v 1.4 2008/04/04 10:13:59 xtraeme Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <dev/sysmon/sysmonvar.h>
#include <dev/spi/spivar.h>
struct tmp121temp_softc {
struct spi_handle *sc_sh;
struct sysmon_envsys *sc_sme;
envsys_data_t sc_sensor;
};
static int tmp121temp_match(device_t, cfdata_t, void *);
static void tmp121temp_attach(device_t, device_t, void *);
static void tmp121temp_refresh(struct sysmon_envsys *, envsys_data_t *);
CFATTACH_DECL_NEW(tmp121temp, sizeof(struct tmp121temp_softc),
tmp121temp_match, tmp121temp_attach, NULL, NULL);
static int
tmp121temp_match(device_t parent, cfdata_t cf, void *aux)
{
struct spi_attach_args *sa = aux;
/* configure for 10MHz */
if (spi_configure(sa->sa_handle, SPI_MODE_0, 1000000))
return 0;
return 1;
}
static void
tmp121temp_attach(device_t parent, device_t self, void *aux)
{
struct tmp121temp_softc *sc = device_private(self);
struct spi_attach_args *sa = aux;
aprint_naive(": Temperature Sensor\n");
aprint_normal(": TI TMP121 Temperature Sensor\n");
sc->sc_sh = sa->sa_handle;
sc->sc_sme = sysmon_envsys_create();
sc->sc_sensor.units = ENVSYS_STEMP;
strlcpy(sc->sc_sensor.desc, device_xname(self),
sizeof(sc->sc_sensor.desc));
if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) {
sysmon_envsys_destroy(sc->sc_sme);
return;
}
sc->sc_sme->sme_name = device_xname(self);
sc->sc_sme->sme_refresh = tmp121temp_refresh;
sc->sc_sme->sme_cookie = sc;
if (sysmon_envsys_register(sc->sc_sme)) {
aprint_error_dev(self, "unable to register with sysmon\n");
sysmon_envsys_destroy(sc->sc_sme);
}
}
static void
tmp121temp_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
{
struct tmp121temp_softc *sc = sme->sme_cookie;
uint16_t reg;
int16_t sreg;
int val;
if (spi_recv(sc->sc_sh, 2, (uint8_t *)&reg) != 0) {
edata->state = ENVSYS_SINVALID;
return;
}
sreg = (int16_t)be16toh(reg);
/*
* convert to uK:
*
* TMP121 bits:
* D15 : sign bit
* D14-D3 : data (D14 is MSB)
* D2-D0 : zero
*
* The data is represented in units of 0.0625 deg C.
*/
sreg >>= 3;
val = sreg * 62500 + 273150000;
edata->value_cur = val;
edata->state = ENVSYS_SVALID;
}